Degree days for root, bulb, and leafy vegetable pests

Here are the degree days accumulated from April 1st until May 12th –15th, 2011.

Area

Onion Maggot

Cabbage Maggot

Carrot Rust Fly

GDD

As of

Bradford/ Holland Marsh*

166.6

N/A

203.4

133.3

13/05/2011

Sarnia

177.3

124.5

210.9

148.8

12/05/2011

London

233.1

168.0

270.2

199.3

15/05/2011

Wellington

169.4

111.3

202.2

139.1

15/05/2011

Windsor

274.0

198.5

316.0

225.3

15/05/2011

Area

Carrot Weevil

Tarnished Plant Bug

Leafhopper

GDD

As of

Bradford/ Holland Marsh*

81.2

10.3

40.9

133.3

13/05/2011

Sarnia

91.3

30.6

68.2

148.8

12/05/2011

London

138.7

37.7

87.4

199.3

15/05/2011

Wellington

84.9

13.0

44.5

139.1

15/05/2011

Windsor

168.1

54.9

115.2

225.3

15/05/2011

* Data provided thanks to Muck Crops Research Station, Department of Plant Agriculture, University of Guelph

Degree day information for pests

Degree Days

1st Generation

2nd Generation

3rd Generation

Onion Maggot

210

1025

1772

Cabbage Maggot

314-398

847-960

1446-1604

Carrot Rust Fly

329 – 395

1399-1711

n/a

Carrot Weevil

138 – 156
455 (90% oviposition)

No model
available

n/a

Tarnished Plant Bug

40

n/a

n/a

Aster Leafhopper

128

390

n/a

Enough degree days have accumulated indicating the emergence of 1st generation adults of onion maggot and the beginning of egg-laying for carrot weevil in the London and Windsor areas. Also in the Windsor area, the emergence of overwintering carrot rust fly adults and the hatching of overwintering aster leafhopper eggs is soon approaching. Still awaiting enough accumulations in the other areas.